Calories in Lemons: Nutrition Facts & Serving Sizes
Per 1 cup, sections (212g)
Per 100g
Source: USDA FoodData Central, SR Legacy, March 2026.
One medium lemon (84g) contains just 24.4 calories, making it an essentially negligible calorie addition to any meal or drink. Per 100g, lemons provide 29 calories, 1.1g of protein, 9.3g of carbs (including 2.8g of fiber), and only 0.3g of fat. The standout nutrient is vitamin C at 53mg per 100g, covering about 59% of the daily recommended intake in a single lemon. Lemons are primarily used as a flavoring agent rather than eaten whole, so calorie contribution is minimal in most uses. Lemon juice squeezed over meals adds almost no calories while enhancing flavor and providing vitamin C. The 2.8g of fiber per 100g comes mostly from pectin in the peel. Lemons also provide 138mg of potassium per 100g and 11mcg of folate. The citric acid in lemons may help with kidney stone prevention by increasing urinary citrate, which reduces calcium oxalate crystal formation. Lemon water is a popular daily habit for hydration, vitamin C intake, and appetite control.
Nutrition Highlights
Calories by Serving Size
| Serving | Cal | Protein | Carbs | Fat | Fiber |
|---|---|---|---|---|---|
| 1 cup, sections (212g) | 61.5 | 2.3g | 19.7g | 0.6g | 5.9g |
| 1 fruit (2-3/8" dia) (84g) | 24.4 | 0.9g | 7.8g | 0.3g | 2.4g |
| 1 fruit (2-1/8" dia) (58g) | 16.8 | 0.6g | 5.4g | 0.2g | 1.6g |
| 1 serving (58g) | 16.8 | 0.6g | 5.4g | 0.2g | 1.6g |
| 1 wedge or slice (1/8 of one 2-1/8" dia lemon) (7g) | 2 | 0.1g | 0.7g | 0g | 0.2g |
| 100g | 29 | 1.1g | 9.3g | 0.3g | 2.8g |
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Full Nutrition Facts (per 100g)
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Calories | 29 | 1% |
| Protein | 1.1g | 2% |
| Total Fat | 0.3g | |
| Total Carbohydrates | 9.3g | 3% |
| Dietary Fiber | 2.8g | 10% |
| Sugars | 2.5g | 5% |
| Sodium | 2mg |
Vitamins & Minerals (per 100g)
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Calcium | 26mg | 2% |
| Iron | 0.6mg | 3% |
| Potassium | 138mg | 3% |
| Vitamin A | 1mcg | 0% |
| Vitamin C | 53mg | 59% |
| Vitamin B6 | 0.1mg | 6% |
| Magnesium | 8mg | 2% |
| Phosphorus | 16mg | 1% |
| Zinc | 0.1mg | 1% |
| Selenium | 0.4mcg | 1% |
| Folate | 11mcg | 3% |
| Niacin (B3) | 0.1mg | 1% |
% Daily Values based on a 2,000 calorie diet (FDA reference).
Health Benefits of Lemons
Lemons are one of the best vitamin C sources available. At 53mg per 100g, a single medium lemon covers over half the daily vitamin C requirement. Vitamin C is essential for collagen synthesis, which supports skin health, joint integrity, and muscle tissue repair. For athletes, adequate vitamin C also reduces oxidative stress caused by training and may shorten recovery time from illness.
Vitamin C also significantly enhances non-heme iron absorption from plant foods. Squeezing lemon juice over iron-rich vegetables like spinach or lentils can increase iron absorption by up to 67%. This is particularly useful for those eating plant-based diets or anyone falling short on iron intake.
The citric acid in lemons may reduce the risk of kidney stones. Studies show that dietary citrate inhibits calcium oxalate crystal formation in urine. Drinking water with lemon juice regularly is a common recommendation for those prone to calcium kidney stones.
Lemon juice added to water has been promoted as an appetite control strategy. While the evidence is modest, some research suggests acidity from citric acid may slow gastric emptying slightly, helping you feel fuller for longer.
The folate content at 11mcg per 100g and potassium at 138mg contribute meaningfully when lemons are consumed as whole fruit or juice rather than just as a flavoring.
Dietary Considerations
Lemons are naturally gluten-free, vegan, dairy-free, and extremely keto-friendly at only 9.3g of carbs per 100g with 2.8g of fiber. For weight loss, lemons are essentially calorie-free when used as a flavoring. Drinking lemon water is a popular strategy for staying hydrated and adding vitamin C without adding calories. The acidity of lemon juice may erode tooth enamel with excessive consumption, so drinking lemon water through a straw and rinsing with plain water afterward is recommended. Lemons are safe for all common dietary restrictions.
Daily Intake (100g)
100g of lemon provides 1% of a 2,000-calorie diet.
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Frequently Asked Questions
How many calories in a lemon?
One medium lemon (84g) contains 24.4 calories. A smaller lemon (58g) has about 16.8 calories. Per 100g, lemons have 29 calories. When used as a juice or flavoring, the calorie contribution is negligible.
Is lemon good for weight loss?
Lemon is great for weight loss as a flavoring agent or in lemon water. It adds minimal calories (a whole lemon is only 24 calories) while providing vitamin C and citric acid that may help with satiety. Adding lemon juice to water can make it more enjoyable to stay hydrated throughout the day.
How much vitamin C is in a lemon?
A medium lemon (84g) contains about 44.5mg of vitamin C. Per 100g, lemons provide 53mg, covering roughly 59% of the daily recommended intake. Vitamin C supports immune function, collagen production, and iron absorption.
How much protein in a lemon?
A medium lemon (84g) has 0.9g of protein. Per 100g, lemons contain 1.1g of protein. Lemons are not a protein source and are used primarily for their vitamin C content, flavor, and citric acid properties.
Is lemon keto-friendly?
Yes, lemons are very keto-friendly. A whole medium lemon has only 7.8g of carbs and 2.4g of fiber. Squeezed as juice over meals or in water, a tablespoon of lemon juice adds fewer than 3 calories and minimal carbs. Lemon works well in keto recipes and drinks.
What does lemon water do for your body?
Lemon water provides vitamin C (about 15-20mg per glass depending on lemon amount), stays low-calorie, and some research suggests citric acid may support kidney stone prevention. It does not significantly boost metabolism or detox the body despite popular claims. Its main benefit is making plain water more enjoyable, which supports hydration.
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